Such a discovery was possible because the dinosaur's skin fossilized before bacteria had a chance to eat up the tissue.

It is "absolutely amazing to be able to identify organic molecules from soft tissue that belonged to a beast that died over 66 million years ago," said Manning, whose work with the fossil was partially funded by the National Geographic Expeditions Council. (The National Geographic Society owns National Geographic News.)

But scientists do know that the body was probably buried rapidly. The resulting low-oxygen environment and the apparent lack of disturbance to the site made Dakota a "world-class dinosaur" fossil, according to the new study, published July 1 in the journal Proceedings of the Royal Society B.